- Synthesis and utility of the 3,3-dimethyl-5-substituted-2-pyrrolidinone 'Quat' chiral auxiliary
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The synthesis and utility of the 3,3-dimethyl-5-substituted-2-pyrrolidinone 'Quat' chiral auxiliary in stereoselective enolate reactions of attached N-acyl side chains combined with the mild and non-racemising conditions required for the ultimate removal of the chiral side chain is described.
- Davies, Stephen G.,Dixon, Darren J.,Doisneau, Gilles J.-M.,Prodger, Jeremy C.,Sanganee, Hitesh J.
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p. 647 - 658
(2007/10/03)
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- Asymmetric aldol and alkylation reactions mediated by the 'quat' chiral auxiliary (R)-(-)-5-methyl-3,3-dimethyl-2-pyrrolidinone
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Enolates derived from the N-propionoyl derivative of the 'quat' chiral auxiliary (R)-(-)-5-methyl-3,3-dimethyl-2-pyrrolidinone undergo highly stereoselective aldol and alkylation reactions. Removal of the auxiliary has been demonstrated with LiOH, PhCH2OLi, MeOMgBr and LiAlH4 to generate respectively (2R,3R)-3-hydroxy-2-methyl-3-phenylpropionic acid in homochiral form, and with 96% e.e. (S)-2-methyl-3-phenylpropionic acid and derived methyl and benzyl esters and with >94% e.e. (S)-2-methyl-3-phenylpropanol.
- Davies,Doisneau,Prodger,Sanganee
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p. 2373 - 2376
(2007/10/02)
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- Synthesis of 5-substituted-3,3-dimethyl-2-pyrrolidinones: "Quat" chiral auxiliaries
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The synthesis of a series of chiral auxiliaries, 5-substituted-3,3-dimethyl-2-pyrrolidinones, "quats", from L-glutamic acid is described. Efficient regeneration of the chiral auxiliaries from their N-pivaloyl derivatives is readily achieved with LiOH in THF-water at 20°C.
- Davies, Stephen G.,Doisneau, Gilles J. -M.,Prodger, Jeremy C.,Sanganee, Hitesh J.
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p. 2369 - 2372
(2007/10/02)
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